Metapopulation Spatial–Temporal Distribution Patterns of Mediterranean Fruit Fly (Diptera: Tephritidae) in a Patchy Environment

We studied the large-scale spatialÐtemporal distribution pattern of the Mediterranean fruit sy, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) to understand whether long-term dispersal may affect its maintenance in a highly patchy and isolated arid environment. The study area contained few dispersed settlements and agricultural plots covering 3,000 km 2 , ranging from 100 to 900 m in altitude in southern Israel. Due to the arid nature of the study area, no wild hosts existed outside the settlements. Data were collected from three settlements at different altitudes from 1999 to 2002. During 2000, adult sies were monitored throughout the entire area. Data were incorporated into a geographic information system, and weekly spatial distribution charts were produced and analyzed. Our results suggest that, within the study area, C. capitata overwinters in sites 400 mi n altitude with abundant winter hosts but not at higher altitudes. In remote settlements and agricultural areas at higher altitudes, sies reappeared every year in midsummer, which can only be explained by annual migration from the lower altitudes. Our results demonstrate that sies migrate at least 50 km, probably over a single generation, before reaching some of the remote havens within the study area. This long-distance migration has far-reaching consequences for maintenance of remote populations and should be taken into consideration for future basic research and applied control practices of C. capitata.